U.S. patent number 4,765,923 [Application Number 07/044,932] was granted by the patent office on 1988-08-23 for composition for reducing color contamination of influent water.
This patent grant is currently assigned to Betz Laboratories, Inc.. Invention is credited to Gerald C. Walterick, Jr..
United States Patent |
4,765,923 |
Walterick, Jr. |
August 23, 1988 |
Composition for reducing color contamination of influent water
Abstract
Methods and compositions for reducing organic color
contamination in influent water are disclosed. The methods comprise
adding to the influent water powdered activated carbon and a water
soluble or water dispersible cationic polymer. The polymers are
chosen from: (a) polyquaternary ammonium polymers formed from
reaction of a secondary amine with an epichlorohydrin or epoxide
(b) cross-linked polyquaternary ammonium polymers formed from
reaction of a secondary amine, epichlorohydrin or epoxide, and a
third reactant selected from the group consisting of ammonia,
primary amines, alkylenediamines and polyamines and (c)
substantially linear high molecular weight polyquaternary ammonium
polymers of the type disclosed in U.S. Pat. No. 3,288,770, such as
polydiallyldimethyl ammonium chloride. Compositions comprise a
slurry comprising powdered activated carbon and at least one
polymer chosen from the (a) (b) and (c) groupings and mixtures
thereof.
Inventors: |
Walterick, Jr.; Gerald C.
(Levittown, PA) |
Assignee: |
Betz Laboratories, Inc.
(Trevose, PA)
|
Family
ID: |
26722172 |
Appl.
No.: |
07/044,932 |
Filed: |
May 1, 1987 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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728986 |
Apr 30, 1985 |
4668404 |
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Current U.S.
Class: |
252/181; 523/414;
523/468; 524/495; 524/496; 524/548; 524/555; 524/808; 524/815 |
Current CPC
Class: |
C02F
1/283 (20130101); C02F 1/54 (20130101) |
Current International
Class: |
C02F
1/54 (20060101); C02F 1/28 (20060101); C02F
001/56 () |
Field of
Search: |
;252/181 ;523/414,468
;524/495,496,548,555,808,815 ;502/180 ;423/445,460 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Chem. Abs. 87:90394e (1977). .
Chem. Abs. 89:117244m (1978). .
Chem. Abs. 94:157877e (1981). .
Chem. Abs. 89:117260p (1978). .
"The Mechanism of Flocculation Processes in the Presence of Humic
Substances", Narkis et al., Journal AWWA, Feb. 1975, pp. 101-108.
.
"Chlorination of Organics in Drinking Water", Stevens et al.,
Journal AWWA, Nov. 1976, pp. 615-620. .
"Measurement of Trihalomethane & Precursor Concentration
Changes", Stevens et al., Journal AWWA, Oct. 1977, pp. 546-554.
.
"The Occurence of Organohalides in Chlorinated Drinking Waters",
Bellar et al., Journal AWWA, Dec. 1974, pp. 703-706. .
"The Use of Chloramine for Reduction of Trihalomethanes &
Disinfection of Drinking Water", Brodtmann et al., Journal AWWA,
Jan. 1979, pp. 40-42. .
"Coagulation & Color Problems", Joint Report, Journal AWWA,
May, 1970, pp. 311-314. .
"Removing Color & Chloroform Precursors from Low Turbidity
Waters by Direct Filtration", Scheuch et al., Journal AWWA, Sep.
1981, pp. 497-502. .
"Model Organic Compounds as Precursors of Chloroform Production in
the Chlorination of Water Supplies", Baum et al., American Chemical
Society National Meeting, Mar. 1978. .
Glass et al., "Coagulation & Direct Filtration of Humic
Substances with Polyethylenimines", Env. Sci. & Tech., Mar.
1979, pp. 299-305..
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Primary Examiner: Wax; Robert A.
Attorney, Agent or Firm: Ricci; Alexander D. Tobe; Roslyn
T.
Parent Case Text
This is a division of application Ser. No. 728,986, filed Apr. 30,
1985, now U.S. Pat. No. 4,668,404.
Claims
I claim:
1. A composition for reducing the color contaminant content of
potable influent water, wherein said color contaminant content
comprises a member or members selected from the group consisting of
humic acids, lignins, tannins, and fulvic acids, comprising in
combination:
(a) powdered activated carbon and;
(b) a water soluble or water dispersible cationic polymer selected
from the group consisting of (i) polyquaternary ammonium polymers
formed from the reaction of dimethylamine and epichlorohydrin and
having a molecular weight Mn of about 8,000-14,000 and (ii)
cross-linked polyquaternary ammonium polymers formed from the
reaction of ethylenediamine, dimethylamine, and epichlorohydrin and
having a molecular weight Mn of about 400-600.times.10.sup.3 or
mixtures of (i) and (ii).
2. A composition as recited in claim 1 wherein the weight ratio of
powdered activated carbon to cationic polymer is about 1: about
0.1--about 10.
3. A composition as recited in claim 1 wherein said cationic
polymer (i) has a molecular weight Mn of about 10,000.
4. A composition as recited in claim 1 further comprising a second
cationic polymer wherein said second cationic polymer comprises
polydiallyldimethyl ammonium chloride and wherein the molecular
weight Mn of said second cationic polymer is about
250-400.times.10.sup.3.
5. A composition comprising a slurry which includes (a) powdered
activated carbon, (b) a cationic polymer formed from reaction of
dimethylamine and epichlorohydrin and having a molecular weight Mn
of around 10,000, and (c) polydiallyldimethylammonium chloride
homopolymer having a molecular weight Mn of about
250-400.times.10.sup.3, the weight ratio of components (a):(b+c)
being about 1:0.1-10.
Description
FIELD OF THE INVENTION
The present invention pertains to methods and compositions for
reducing the color content of influent water for potable and/or
industrial use.
BACKGROUND
Influent water treatment is needed to remove contaminants from raw
water to make it suitable for potable or industrial uses. These
contaminants may be either soluble or insoluble, with solubility
dictating the procedure needed for proper removal.
Soluble components are usually removed or minimized via lime/soda
softening, demineralization, etc. Insoluble components may be
reduced or removed by settling or filtration.
Swamps and wetlands often introduce color contaminants into raw
water sources. The problem is particularly acute after heavy
rainfalls. Color in raw water causes various problems including
objectionable taste, increased bacteria and algae growth, fouling
of anion exchange resins, interference with coagulation, and
stabilization of soluble iron and manganese.
Most color in raw water is colloidal in nature and results from
organic material such as humic acids, lignins, tannins, fulvic
acids, and other related compounds that are leached from leaves or
other vegetation.
I have found that such color contamination can be effectively
reduced by the use of a combination of powdered activated carbon
(PAC) and a water soluble or water dispersible cationic
polyelectrolyte.
PRIOR ART
Traditionally, chlorination or coagulation with inorganic salts has
been used to reduce color content. Cationic polymers have also been
used.
Chlorination is problematic in that chlorine reacts with the color
contaminants and is thought to form members of the carcinogenic
trihalomethane genus. As such, chlorination is disfavorably viewed
as a safe means to reduce color content.
The use of PAC as a coagulant aid is well known. For instance, in
U.S. Pat. No. 3,252,899 to Rice et. al., the use of activated
carbon and a polymeric flocculating agent such as polyacrylamide or
hydrolyzed polyacrylamide is stated to remove organic pollutants
from wastewater. Of similar import is U.S. Pat. No. 4,043,904 to
Takeda et. al., which teaches the use of polyacrylamide with PAC to
cleanse wastewaters contaminated with polynuclear surface active
agents.
Other prior art patents and literature references which may be of
interest to the present application include: U.S. Pat. No.
4,239,865 (Tarao et. al.); U.S. Pat. No. 4,320,011 (Sato et. al.);
Chem. Abstract 87:90394e (1977); Chem. Abstract 89:117244m (1978);
Chem. Abstract 94:157877e (1981); and Chem. Abstract 89:117260p
(1978).
The present invention, as it uses a combination of cationic polymer
and PAC is viewed as an improvement in the art since it not only
effectively reduces color content but also avoids the heretofore
mentioned problems associated with chlorination.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the invention, treatment comprising PAC and a
water soluble or water dispersible cationic polyelectrolyte is
utilized to reduce the color contamination content of influent
water. These components are preferably admitted to the influent,
raw water at a location or locations upstream from a softening,
clarification or filtration process.
The first component of the system is powdered activated carbon.
This is available commercially from a variety of sources.
The second component is a water soluble or dispersible cationic
polyelectrolyte polymer or polymers chosen from the groupings (I),
(II) (III) as hereinafter defined.
Polymers belonging to the first (I) grouping include water soluble
or dispersible polyquaternary ammonium polymers of the type
disclosed in U.S. Pat. No. Re. 28,807 (Panzer et. al.). The entire
disclosure of this reissue patent is hereby incorporated by
reference herein.
As is stated in that reissue patent, the polyquaternary polymers of
cationic polymer group (I) are derived from reaction of secondary
amines, such as dialkylamines, and difunctional epoxide compounds
or precursors thereof.
In accordance with the reissue patent disclosure, the water
dispersible polyquaternary polymers, used as the second component
in the present invention, consist essentially of the repeat units
##STR1## wherein R and R.sub.1 are independently selected from the
group consisting of lower alkyl (1-3 carbon atoms). E is the
residue obtained after bifunctional reaction of a compound selected
from the group consisting of epihalohydrins, diepoxides, precursors
for epihalohydrins and diepoxides, and mixtures thereof. m and n
are integers of substantially equal value. X.sup..crclbar.
represents the anion forming a portion of the polyquaternary
compound. In summary, the polymers (group I) involve only two
reactants: a lower dialkylamine, and a difunctional epoxy type
reactant.
As to the epoxy reactant, epihalohydrins such as epichlorohydrin
and epibromohydrin may be mentioned. Epichlorohydrin is preferred.
Diepoxides such as 1,4-butanediol-diglycidyl ethers are also
useful. Precursors for epihalohydrins and diepoxides are also
useful. Exemplary precursors include: 1,3-dichloropropanol-2 and
1,4-dichloro,2,3-dihydroxybutane.
As to the secondary amines which may be used as reactants, these
include dimethylamine, diethylamine, dipropylamine, and secondary
amines containing mixtures of alkyl groups having 1 to 3 carbon
atoms.
Exact reaction parameters may be gleaned from perusal of
aforementioned U.S. Pat. No. Re. 28,807 and need not be repeated
here. Suffice it here to say that the preferred polymer of group I
is formed from dimethylamine and epichlorohydrin reaction. Such
reaction is detailed in Example 1 of the reissue patent.
The preferred polyquaternary polymer of group I is thought to have
the structure: ##STR2##
The molecular weight of this polymer is approximately 10,000. The
particular molecular weight is not critical as long as the polymer
remains water soluble or water dispersible.
As to the group (II) cationic polymers which may be used in
accordance with the invention, these may be generically
characterized as cross-linked polyquaternary ammonium polymers and
are described in detail in U.S. Pat. No. Re. 28,808 (Panzer et.
al.). The entire disclosure of this reissue patent is hereby
incorporated by reference herein.
As is stated in the U.S. Pat. No. Re. 28,808, the water dispersible
polyquaternary polymer consists essentially of repeating units.
##STR3## wherein R, R.sub.2, E, m, and n are the same as given
above for the polymer (I) grouping.
A is the residue obtained after bifunctional reaction of a
polyfunctional polyamine selected from the group consisting of
ammonia, primary amines, alkylene diamines of 2 to 6 carbon atoms,
polyalkylpolyamines of the structure ##STR4## wherein y represents
an integer of about 1 to 5, R.sub.3 is an alkylene radical of about
2 to 6 carbon atoms, and R.sub.4 is selected from the group
consisting of hydrogen, alkyl of about 1 to 3 carbon atoms, and
.omega.-aminoalkyls of about 2 to 6 carbon atoms, a polyglycolamine
of a structure such as ##STR5## wherein a is an integer of about 1
to 5, piperazine heteroaromatic diamines of the structure ##STR6##
wherein q is zero or an integer of about 1 to 3, aromatic diamines
of the structure ##STR7## wherein q is zero or an integer of about
1 to 3, and polyaminepolybasic acid condensation products of
molecular weight up to about 10,000; X.sup..crclbar. is an ion
forming the anionic portion of said polyquaternary compound; m and
p are integers which represent molar quantities of amine reactants,
the ratio of m to p being from about 99:1 to 85:15; n represents
the molar quantity of E forming the principal chain of said
polyquaternary, the molar quantity represented by n being
substantially equal to the sum of the molar quantities of m and p;
said polyfunctional amine containing in addition to the amount of E
required for difunctional reaction therewith an amount of E which
is from zero to about the full functional equivalency remaining in
said A; the sum of m, n and p being such as to provide a
polyquaternary compound which as a 37% aqueous solution, by weight,
based on the total weight of the cationic portion of said
polyquaternary has a viscosity at 25.degree. C. of at least=100
centistokes and Z is an integer such as to satisfy anion
requirements of the polyquaternary compound.
In summary, the group II polymers are formed from three reactants:
a lower dialkylamine (C.sub.1 -C.sub.3), a difunctional epoxy type
reactant (the same as in the Group I polymers) and a third reactant
selected from the group consisting of ammonia, primary amines,
alkylenediamines of from 2-6 carbon atoms, and polyamines as
defined hereinabove for A.
Exact reaction parameters for the group II cationic
polyelectrolytes are specified in aforementioned U.S. Pat. No. Re.
28,808 and need not be repeated here. The preferred group II
polymer is a cross-linked polyquaternary polymer formed from
ethylenediamine, dimethylamine and epichlorohydrin (see for
instance Example 2 of U.S. Pat. No. Re. 28,808).
The preferred group II polymer is thought to have the structure:
##STR8##
The molecular weight Mn of this polymer is
400-600.times.10.sup.3.
Cationic polymers of Group III are disclosed in U.S. Pat. No.
3,288,770 (Butler). The entire disclosure of this U.S. Pat. No.
3,288,770 is hereby incorporated by reference herein.
To paraphrase the U.S. Pat. No. 3,288,770 these particular high
molecular weight polyquaternary polymers are characterized as
having a linear homopolymer chain of repeat units having one of the
formulae: ##STR9##
It will be appreciated that, with each such cationic ammonium
group, there is associated a chloride anion.
In the above formulae, the symbols D and F independently represent
an alkyl, hydroxyalkyl, or phenyl radical which may contain as
substituents such groupings as amido, carboloweralkoxy,
loweralkoxy, mono- and dicyclic aryloxy, cyano, thioloweralkoxy,
thiophenoxy, or lower alkoyl (forming a ketonic group) radicals, 5-
and 6-membered cycloalkyl groupings, and, on the alkyl groupings
only, a nitro group, and on the phenyl radical only, a halogen atom
(chlorine, bromine, fluorine, and iodine).
The symbols G and G' independently represent a hydrogen, chloro,
bromo, or lower alkyl or phenyl radical, having substituents as
stated under the definition for D and F above.
The symbol K stands for a divalent radical of the formula:
The symbol J stands for a divalent radical of the formula:
The symbol L stands for a divalent radical of the formula:
In these last-mentioned formulae, the small letter s represents one
of the numbers 0 and 1; the small letter u represents one of the
numbers 1 and 2; and the small letter w represents one of the
numbers 2 and 3.
See Col. 2 & 3, U.S. Pat. No. 3,288,770.
After the issuance of the U.S. Pat. No. 3,288,770, the following
formula has been reported as being characteristic of the preferred
polymer of group III, namely polydiallyldimethyl ammonium chloride
(DADMAC): ##STR10##
This preferred polymer of Group III has been reported to have a
molecular weight (Mn) of between about 250-400.times.10.sup.3. It
is noted that the molecular weight of this third component (as well
as for the polymers of groups I and II) is not critical as long as
the polymer remains water soluble or water dispersible.
Methods for producing the polymers of the Group III grouping of the
invention need not be reported in detail herein, as they are
reported in the aforementioned U.S. Pat. No. 3,288,770. The
preferred DADMAC polymer of Group III, for instance, may be
prepared in accordance with the disclosure of Example 1 of said
U.S. Pat. No. 3,288,770.
The amounts of the treatment components to be fed to the system
will vary in accordance with such factors such as: amount of color
contamination present in the influent water, water pH, and
temperature.
The following treatment ranges, given in terms of ppm (based upon
one million parts water) are contemplated:
Component One--P.A.C.--1 ppm to 5,000 ppm, with a range of 5
ppm-200 ppm being preferred;
Component Two--a water soluble or dispersible cationic
polyelectrolyte chosen from the above groupings (I) (II) or
(III)--based upon 100% actives polymer--0.1-2,500 ppm. It is noted
that mixtures of polymers from the groupings (I) (II) and (III) are
also within the purview of the invention. A range of from about
1-1,250 ppm of the cationic polymer is preferred.
Compositions in accordance with the invention comprise a slurry of
P.A.C. and cationic polymer. If necessary, stabilizing agents such
as polysaccharides, etc., may be used to enhance the flow
characteristics of the slurry.
Contemplated weight ratios of the slurry components may vary as
follows: (parts by weight)
P.A.C.--1 part
Cationic Polymer--0.1-10
At present, the composition preferred for use is (based upon one
part by weight P.A.C.)
Component 1--Powdered Activated Carbon--1 part
Component 2--Condensation Polymer of dimethylamine and
epichlorohydrin; structure: ##STR11## Mn.apprxeq.8,000-14,000,
present in an amount of about 0.225 parts based upon 1 part P.A.C.;
a group I polymer, and a group III polymer
comprising--polydiallyldimethyl ammonium chloride, structure
##STR12## molecular weight (Mn) 250-400.times.10.sup.3, present in
an amount of about 0.075 parts based upon 1 part of P.A.C.
EXAMPLES
In order to demonstrate the efficacy of the invention in reducing
color content of treated water, color reduction tests were
undertaken with Florida well water samples. The procedure used was
a basic jar test in which the beakers were mixed simultaneously by
a gang stirrer. Color determinations were made using a Hach
Spectrophotometer. Results appear below in the following
tables.
Procedure:
(1) 200 mL of Florida well water added to a 400 mL beaker;
(2) each filled beaker is mixed at 100 rpm using a stirrer equipped
with a 1" by 2" paddle;
(3) treatment added at dosage indicated hereinbelow;
(4) treated water samples mixed 30 minutes at 100 rpm;
(5) mixing stopped. Samples allowed to settle for 10 minutes;
(6) supernatant water from each beaker sampled for analysis.
TABLE 1 ______________________________________ Test Water: Florida
Well Water Turbidity = 2.0 ntu pH = 7.0 True Color = 80 color units
Treatment Dosages 100% Actives Basis Supernatant Polymer "A" PAC
True Color Treatment Added (ppm) (ppm) (color units)
______________________________________ None -- -- 70 Polymer
"A"/PAC Blend 6 50 9 Polymer "A" 6 -- 15 P.A.C. -- 50 66
______________________________________ Polymer "A" = condensation
polymer of dimethylamine and epichlorohydrin, .sup.--mw .apprxeq.
10,000, structure ##STR13## group I polymer
TABLE 2 ______________________________________ Test Water: Florida
Well Water pH = 7.0 Turbidity = 2.0 ntu True Color = 80 color units
______________________________________ Treatment Dosages 100%
Actives Basis Supernatant Polymer "B" PAC True Color Treatment
Added (ppm) (ppm) (color units)
______________________________________ None -- -- 70 Polymer
"B"/PAC Blend 3 50 16 Polymer "B" 3 -- 23 P.A.C. -- 50 66
______________________________________ Polymer "B" = DADMAC polymer
a group III polymer; molecular weight 250-40 .times. 10.sup.3
(--Mn)
TABLE 3 ______________________________________ Test Water: Florida
Well Water pH = 7.0 Turbidity = 2.0 ntu True Color = 80 color units
______________________________________ Treatment Dosages 100%
Actives Basis Poly- Poly- mer mer Supernatant A B PAC True Color
Treatment Added (ppm) (ppm) (ppm) (color units)
______________________________________ None -- -- -- 70 Polymer
"A"/Polymer 4.5 0.75 50 16 "B"/PAC Blend Polymer "A"/Polymer 4.5
0.75 -- 23 "B" P.A.C. -- -- 50 66
______________________________________ Polymer "A"= same as Table 1
Polymer "B"= same as Table 2
TABLE 4 ______________________________________ Test Water: Florida
Well Water pH = 8.2 Turbidity = 1.0 ntu True Color = 53 color units
______________________________________ Treatment Dosages 100%
Actives Basis Supernatant Polymer "C" PAC True Color Treatment
Added (ppm) (ppm) (color units)
______________________________________ None -- -- 49 Polymer
"C"/PAC Blend 7.5 50 15.5 Polymer "C" 7.5 -- 19.0 P.A.C. -- 50 37.5
______________________________________ Polymer "C" = polymer of
Group II; crosslinked polyquaternary polymer formed from
ethylenediamine, dimethylamine, and epichlorohydrin, molecula
weight --Mn .apprxeq. 400 -600 .times. 10.sup.3 -
In accordance with the patent statutes, the best mode of practicing
the invention has been herein set forth. However, it will be
apparent to those skilled in the art that many modifications can be
made in the methods and compositions herein disclosed without
departing from the spirit of the invention. It is to be understood
that the scope of the invention is to be limited solely by the
scope of the appended claims:
* * * * *